Gas-engine.



N0. 860,732. PATENTED JULY 23, 1907.

N. CRANE. GAS ENGINE.

APPLICATION FILED 83191217, 1904.

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UNITED STATES PATENT OFFICE.

NEWTON CRANE, OF BOSTON, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

ELLIOT C. LEE, OF BROOKLINE, MASSACHUSETTS.

GAS-ENGINE.

Specification of Letters Patent.

Patented July 23, 1907.

Application filed September 17,1904. Serial No. 224.874.

To all whom it may concern:

Be it known that I, blnw'ror. CRANE, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Gas-Engines, of which the following is a specification.

This invention relates to internal combustion engines, and has for its object to provide an engine which is balanced both explosively and mechanically.

A further object of the invention is to so organize the several elements that the engine is especially adapted to be employed for motor-vehicles and motor-boats.

On the drawings, forming a part of this specification: Figure l is a top plan view of an engine constructed according to my invention. Fig. 2 is a side elevation of the same. Fig. 3 is an end view thereof. Fig. 4 is a cross section on the line 44 of Fig. 1. Fig. 5 is a section on the line 5-5 of Fig. 3. Fig. 6 is a vertical section of one of the valves.

The same reference characters indicate the same parts wherever they occur.

The greater part of the mechanism is inclosed in a casing composed of a central portion 10 and side pieces 11 11. At one end of said casing are the cylinders 12 12, of which two are shown in this embodiment of the invention. The cylinders 12 are double-ended, each having two oppositely movable pistons 13 13 which operate on the iour-cycle'principle. The combustion of the gas takes place midway between the ends of the cylinders and between the pistons when they are at their inward extreme, thus impelling the pistons of each cylinder simultaneously in opposite directions. By reason of this construction and disposition of energy, the impulse in each cylinder expends its force in opposite directions from a common center, with the result that each piston counterbalances the other. Further than this, the engine is so timed that the explosions in the two cylinders occur alternately, thus distributing the energy still more evenly.

The pistons 13 on one side of the engine are connect' ed by connecting-rods 14 to arms 15 on a rock-shaft 16, journaled in suitable bearings on one side of the frame or casing, and the pistons on the other side of the engine are similarly connected to a rock-shaft 16 journaled on the opposite side of the casing. Arms 17 are formed on the shaft 16 near the other end of the engine, and are connected by connecting-rods 18 to a double-throw crank-shaft 19, midway between the shafts 16. The shaft 19 extends from oneend of the engine casing to the inside cylinder 12 and is journaled in suitable bearings formed on the portion 10 of the casing. A suitable momentumor fly-Wheel 20 is affixed to the projecting end of the shaft 19.

It will be observed that the axis of the crank-shaft 19 is at a right angle to the longitudinal median lines of the two cylinders l2 l2, and is located substantially midway between the ends of said cylinders. One of the rock-shafts 16 is above the horizontal plane occupied by said shaft, and the other is at an equal distance below it, the purpose of this being to cause the piston in one end of a cylinder to move at the same speed as the other piston, since by this arrangement I the variation in the angularity of the rocker-arms and pitmen is the same for one piston as for the other. The arms 15 and 17 of the upper rock-shaft 16 extend downwardly from said shaft, whereas the corresponding arms on the lower rock-shalt project upwardly.

Thus far the description has dealt only with the mechanically-balanced connections by which the pistons effect the driving of the crank-shaft. I will now describe more fully the operation of the pistons and the valve-mechanism.

Referring to Fig. 4, it will be seen that the inner end of the shaft 19 is provided with a pinion 21 which drives, through an intermediate gear 22, a gear 23 affixed to a cam-shaft 24. The gears 21, 22 and 23 are inclosed in the portion 10 of the casing. 24 is journaled in suitable bearings projecting from the valve-casing 25 located over the cylinders 12 12, and it carries the cams 26 which actuate the valves 27 for the admission and exhaustion of the gas.

The valve-casing 25 comprises an admission chamber 28 which receives gas through a supply-tube 29, and an exhaust chamber 30 from which the exhaust is conducted by a tube 31. The valves 27 control the open ends of tubular members 32, of which two are removably installed in the admission chamber and two in the exhaust chamber. One of said tubular members in the admission chamber, and one in the exhaust-chamber, open into one cylinder, and the other members in both chambers open into the other cylinder. Each member 32 has a port 33 which connects the interior thereof with the chamber in which it is installed, thus completing a passage from each cylinder to each chamber.

Each valve is afiixed to a valve-stem 34 which projects through the top of the member 32 above the casing 25. The valve is normally held against its seat on the member 32 by a spring 35.

36 and 37 are actuating levers which are caused by the earns 26 to depress the valve-stems 34 and consequently the valves 27. The levers 36 actuate the admission valves and the levers 37 actuate the exhaustvalves. Said levers are loosely mounted upon a rod 38 which is secured across the valve-casing 25 in suitable fixtures thereon. The levers are suitably spaced by collars 39 on the rod 38, and are held in contact with the cams 26 by torsional springs 40 coiled about the rod.

The pinion 21 on the main shaft 19 is provided with onehalf as many teeth as the gear 23 on the cam-shaft 24, thus causing the said cam-shaft to revolve at onehalf the speed of the main shaft, and so to operate the valves in correct time for a four-cycle movement. An

The cam-shaftelectric spark-plug 41 for each cylinder is adapted tobe connected in the usual way, toignite each charge of gas as it is compressed.

As a whole, the engine is compact and convenient in form, as well as smooth running. The oppositely-moving pistons and roek-shaftscounteract the vibrationof each other, and together with the double-throw crankshaft and oppositely-moving connecting-rods produce an engine especially adapted for high speed and light vehicles;

Although the number of'cylinders shown is two, the

number is not arbitrary. And While the cylinders shown are double-ended and have two pistons each, it is evident that single cylinders and pistons similarly arranged and equally connected to the rock-shafts might'be employed Without departing from the spirit and scope of the invention.

' Having thus explained the nature of the invention, and described a way of constructing and using the same, although without attempting to set forth all of the forms in which it may be made, or all of the modes of its use, I declare that what I claim is 1. An internal combustion engine comprising two parallel rock-shafts, pistons movable in opposite directions between said rock-shafts, cylinders for said pistons, con nections between one rock-shaft and the pistons movable in one direction, connections between the other rock-shaft and the pistons movable in the opposite direction, a crankshaft at one side of said cylinders and between and parallel to said rock-shafts, and connections between said crankshaft and rock-shafts.

2. An internal combustion engine comprising two parallel rock-shafts, one or more cylinders between and at right angles to said rock-shafts, oppositely movable pistons in each ofsaid cylinders, those movable in one direction being connected to one rock-shaft, and those movable in the other direction being connected to the other rockshaft, .21 crank-shaft at one side of-said cylinders between and parallel to said rock-shafts and connections between said crank-shaft and rock-shafts.

3. An internal combustion engine comprising two parallel rock-shafts, one or more cylinders between and at right angles to said rock-shafts, one of said shafts being, above the axes of said cylinders and the other shaft being an equal distance below said axes, oppositely movable pistons in said cylinders, those movable in one direction being connected to one rock-shaft and those movable in the opposite direction being connected to the other rock-shaft, a crank-shaft at one side of said cylinders and between and parallel to said roclcshatts, and connections between said crankshaft and roclvshafts.

In testimony whereof I have ailixed my signature, in presence of two witnesses.

NEWTON CRANE.

Witnesses M. B. MAY, C. C. S'rnennn. 

